This will replace the `include_special_cased_deps` flag

This will replace the `include_special_cased_deps` flag

…deps_predicate=always_traverse`

…ations

closure functions have a useless hash. The hash of a function does not
account for any closure vars, including unhashable mutable vars,
so that hash is not reliable.
Plus, every instance of a closure will have a different id, so there cannot be
any reuse of anything cached based on the function's hash.

Using a frozen dataclass bypasses these issues. We include the class's __call__ function
as a field in the parent dataclass so that it is part of
the __hash__ function generated by the
@DataClass decorator. Using the class's __call__ is more stable than using an instance's function.

This tests 2 things:
- that subclasses without an @DataClass decorator are still frozen
- that mypy says the types of _callable and __call__ are compatible

For the mypy issue, I tried using Self instead of Any, but Self resolved to ShouldTraverseDepsPredicate which did not match SkipDepsTagOrTraverse for some reason.

Co-authored-by: Joshua Cannon <joshdcannon@gmail.com>